Frost covers

In my book on gardening with frost, one suggestion the author made was to use bubble wrap for an emergency cover. I have access to scads of that stuff that window blinds come packed in. It always bothers me to throw this stuff away. This was a use I had not even thought of and wanted to pass it on.

While frost blankets are great, sometimes a bit extra is needed if a sudden drastic drop threatens even the cool weather crops or as an extra layer under your hoop house.

Gwynn

PM staf with this, or get him involved somehow. He tried it and wasn't impressed. But, I would imagine if you have infinite supplies, a couple layers would do really well. Remember, plastic is a terrible insulator. The air bubbles will equalize pretty quickly if they only have a couple layers of plastic between them. But, staf will give better advice on this particular subject.

Old Hippie wrote:In my book on gardening with frost, one suggestion the author made was to use bubble wrap for an emergency cover. I have access to scads of that stuff that window blinds come packed in. It always bothers me to throw this stuff away. This was a use I had not even thought of and wanted to pass it on.

While frost blankets are great, sometimes a bit extra is needed if a sudden drastic drop threatens even the cool weather crops or as an extra layer under your hoop house.

Gwynn

Another option might be to also include a layer of newspaper a few sheets thick under the plastic. In one of my books the author used flower pots and laths of wood on top of them to hold two sheets of newspaper above the plants in his unheated greenhouse. If plants aren't above your grid maybe it'd work with the paper on top of the grid.

I've also used thick lumps of polystyrene around plants to keep the warmth in the soil and these usefully held up a cover above them.

Hey Old Hippie !

I did try to use bubble wrap last year for season extension in the fall. For me at least , it was a disaster. Now I'm not saying it won't work because I still believe it will. Bubble wrap can trap air between the bubbles and create that dead air space you are looking for. However, I had the basic hoop construction over my beds and I just could not get it to cover the hoops effectively enough. It blew everywhere and even if I could "entomb" the bed, I would not be able to access it without cutting it back or unwrapping it. If you are looking for a quick fix for a night or two, I just don't think you can go out there and wrap the bed. You would have to buy a specialized width, at least 2, preferably 4 foot (online bulk suppliers do this) that would minimize the amount overlapped layers as I found it ssoooooo frustrating trying to duck tape the layers together and create an air tight canopy.

So would i try it again......YES actually but I would create a kind of box cage that Mel suggests for critter control (the one in the pics in book with chicken wire). Bubble wrap does NOT wrap well around curved edges and round shapes like in my hoop house but would easily work better to fit a squared shape with straighter lines. I have thought about it again for the fall and if I did do it again (I still have a lot of bubble wrap left over), I would first build a box frame from wood that goes perfectly over my bed. Find thick cardboard and cut if to cover the frame. Then one layer of bubble wrap (bubbles facing in) taped against thick cardboard (more layers of air) and another layer of bubble wrap on the other side of the cardboard (again with bubbles facing in to the cardboard). I would duck tape where the bubble layers meet and overlap. That should create a very good "dead air space" which is what gives you "R" value or insulation. I would also use some kind of rubber seal used for door insulation on the bottom of the cage where it will touch the box when resting in place to seal that space airtight also. I would then just simply lay plastic over the whole thing to weatherproof it from rain etc.

Hope this helps out. Bubble wrap can and will work with some thought out behind it but beware of trusting it to be able to help you out in a pinch and simply running out there to wrap your garden or lay under your hoops. Its not too user friendly for that purpose in my experience at least, and besides, insulation needs airtight or dead air space to work. Simply laying it over your plants will NOT achieve this.

That is very creative Staf. I hadn't thought of using it the way you did but was thinking of it more as just an extra blanket, put down inside the hoop house or cold frame as an emergency kind of added layer. The idea of the bubbles creating the dead air space intrigues me and seems like it should work. Plastic is not the best insulator as we know, but when you stop and think of it, a lot of greenhouses are made with plastic so why wouldn't the bubble wrap work.

The sizes of it are an issue. I get pieces that are about 8 ft. long but the width is only 2 ft, or a bit less at the widest.

Keep me in the loop with what you do with this and send pics too. Thanks for the info.

Gwynn

Old Hippie wrote:That is very creative Staf. I hadn't thought of using it the way you did but was thinking of it more as just an extra blanket, put down inside the hoop house or cold frame as an emergency kind of added layer. The idea of the bubbles creating the dead air space intrigues me and seems like it should work. Plastic is not the best insulator as we know, but when you stop and think of it, a lot of greenhouses are made with plastic so why wouldn't the bubble wrap work.

The sizes of it are an issue. I get pieces that are about 8 ft. long but the width is only 2 ft, or a bit less at the widest.

Gwynn

Plastic in general is not a good insulator, but with bubble wrap the little air bubble pockets act like double-paned windows. You can actually buy some kinds of bubble wrap for thermal insulation for shipping - foil coated and plain. For those 8' strips, get yourself some clear packing tape, overlap the long edges, and make yourself a bubble-quilt with tape seams! If you can anchor it over some hoops, WHOOOO WEEEEE!

TC